<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>绘制彩虹</title>
    <style>
        .rainbow {
            width: 600px;
            height: 300px;
            border: 2px solid red;
            background-image: radial-gradient(
                /* 圆形 半径 中心点位置 */
                circle 300px at bottom center,
                white 40%,
                pink 50%,
                  pink 55%,
                red 60%,
                red 65%,
                orange 70%,
                orange 75%,
                skyblue 80%,
                skyblue 85%,
                yellow 90%,
                yellow 100%,
                transparent 100%
            );
        }
    </style>
</head>
<body>
    <div class="rainbow"></div>
</body>
</html>
